[Can apps encourage a healthier and more active lifestyle?]

OBJECTIVE: To present an overview of the literature on the effect of smartphone apps and activity trackers on a healthy lifestyle.

DESIGN: Systematic review.

METHOD: PubMed, the Cochrane Library, Embase and CINAHL were searched for relevant articles. Inclusion criteria were: (a) the intervention was a mobile app or activity tracker; (b) that stimulated activity and healthy diet; (c) in adults with an unhealthy lifestyle but so far without medical disorders; (d) aimed at preventative healthcare, improvement in health or healthy behaviour; and (e) measured the effect of physical activity, diet and weight.

RESULTS: We included 17 studies, of which 13 involved apps and 4 involved activity trackers. The effect of the apps on physical activity in overweight or obese people was positive in 6 studies, while no effect was found in 3 studies. There was a positive effect on diet; this was significant in 3 studies and non-significant in 2 studies. The effect on weight was positive in 6 studies, while no effect was found in 5 studies. Evidential value of the studies involving apps was poor to moderate. Activity trackers seemed to have the power to increase physical activity, but quality of these studies was poor. The effects on weight were contradictory and the effects on diet were not investigated.

CONCLUSION: Apps have a global positive effect on physical activity. The effect of apps on diet and weight is unclear, but the trend is that they improve eating patterns. Activity trackers can increase physical activity. Larger scale research with more balanced control groups and longer follow-up is, however, necessary before we can recommend the use of apps and activity trackers.